Effect of TMCP parameters on the microstructure and properties of Q460qNH steel

Abstract

The effects of TMCP parameters, consisting of finish cooling temperature and start rolling temperature in non-recrystallization region, on the final microstructure and mechanical properties of Q460 qNH steel were studied by tensile, Charpy impact tests and optical microscopy. The TMCP parameters for Q460 qNH steel were optimized by laboratory experiments. The results show that the yield strength and tensile strength increase with the finish cooling temperature, and the microstructure of Q460 qNH steel consists of ferrite and granular bainite.

Keywords

TMCP / mechanical properties / M/A constituent / Q460 qNH steel

References

[1] Shen Y., Hansen S. S. Development of a 100ksi (690 MPa) Yield Strength, Weathering Steel for Bridge Applications. Proceedings of the 1995 International Symposium on High Performance Steels for Structural Application[C], 1995 Cleveland, OH, USA ASM International 127-134.

[2] Focht E. M., Montemarano T. W. Development of High Performance Steels for Bridge Construction. Proceedings of the 1995 International Symposium on High Performance Steels for Structural Applications[C], 1995 Cleveland, OH, USA ASM International 141-154.

[3] Komizo Y.-ichi. Recent Development in Steels for Bridge and Line Pipe. The Iron and Steel Institute of Japan. Asia Steel International Conference 2006[C], 2006 Fukuoka, Japan The Iron and Steel Institute of Japan 140-145.

[4] Matsui K., Omori T., Miyata S., . High Performance Steel for Bridge Construction[J]. NKK Technical Review, 1999, 165(3): 11-16.

[5] Abe T., Hashimoto M., Matsui K., . High Strength Atmospheric Corrosion Resisting Steel Plates with Improved Weldability for Bridge Use[J]. NKK Technical Review, 2000, 171(9): 21-26.

[6] Wilson A. D. Properties of Rcent Production of A709 HPS-70W Bridge Steels. ASM International. International Symposium on Steel for Fabricated Structures[C], 1999 Cincinnati, OH, United States ASM International 41-49.

[7] Guo A.-min. Development and Application of New Type Series Bridge Steels[J]. Steel Construction, 2000, 15(3): 53-56.

[8] Wei M., Li Y.-qian. Rolling Process of 14MnNbq Plate on 4200mm Mill[J]. Wide and Heavy Plate, 1999, 5(6): 20-24.

[9] Wang Y.-m., Li M.-y., Wei G. Controlled Rolling and Controlled Cooling of Steel[M], 1995 Beijing Metallurgic Industry Press 37-50.

[10] Wang S.-C., Yang J.-R. Effects of Chemical Composition, Rolling and Cooling Conditions on the Amount of Martensite/Austenite (M/A) Constituent Formation in Low Carbon Bainitic Steels[J]. Materials Science and Egineering, 1992, A154: 43-49.

[11] Chiou C. S., Yang J. R., Huang C. Y. The Effect of Prior Compressive Deformation of Austenite on Toughness Property in an Ultra-low Carbon Bainitic Steel[J]. Materials Chemistry and Physics, 2001, 69(1–3): 113-124.

[12] Mazancová E., Mazanec K. Physical Metallurgy Characteristics of the M/A Constituent Formation in Granular Bainite[J]. Journal of Materials Processing Technology, 1997, 64(1–3): 287-292.

[13] Bhadeshia H. K. D. H., Edmonds D. V. The Mechanism of Bainite Formation in Steels[J]. Acta Metall., 1980, 28(9): 1265-1273.